Improvement of large-scale circulation simulation in an ocean-sea ice model with high-resolution

The impact of the resolution on the large-scale features in an ocean-sea ice coupled model is represented in this paper through three aspects. Firstly, refined resolution accelerates temperature and salinity drifts at a basin-averaged scale by facilitating exchanges among basins, subsequently reducing global-averaged drifts. This amplification of basin-scale exchanges is associated with an accelerated large-scale circulation, leading to a more rapid equilibration of temperature and salinity above 300 meters. Secondly, the refined resolution yields improved simulations of large-scale temperature, salinity, and currents, particularly evident in regions such as the Gulf Stream and its extension. Enhanced current simulations and corresponding temperature distributions contribute to more accurate representations of wind stress through ocean currents and sea surface temperature feedback. This feedback, in turn, influences wind-driven currents, establishing positive feedback loops. Despite little impact on the temporal variability of phenomena such as ENSO, IOD, PDO, and AMO, the refined resolution enhances the strengths of their variabilities. However, spatial patterns of PDO and AMO do not exhibit improvement with refined resolution, potentially attributed to the coarse resolution of the reference dataset.